Ok so like I have posted that I am getting a code, o2 heater sensors. I have put in a 4 new o2 sensors (which werent cheap! :annoyed:) and then when they were switched turned on the car went to take off the code. And those codes had "history" beside them. Anyway the service engine light came on again!!! i dont know what else i can do. So im just taking it to my local cadillac dealer and see if they can fix the problem. :banghead: